JP2016111912A - Motor drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor drive device capable of preventing deterioration of motor efficiency even when a hole element is intermittently driven.SOLUTION: A motor drive comprises: an internal regulator 13 that intermittently drives by intermittently outputting a driving voltage to Hall elements 2U, 2V, and 2W; a drive circuit 11 that generates an applied voltage to be applied to driving windings LU, LV, and LW of a three-phase brushless DC motor M and outputs; Hall amplifiers AmpU, AmpV, and AmpW that detects a zero cross detection timing so that a Hall voltage outputted from the Hall elements 2U, 2V, and 2W is zero-crossed, and generated Hall signals HU, HV, and HW; a rotation control part 12 that drives the drive circuit 11; and an advance value generation part 16 that generates an advance value obtained by adding a zero-cross detection timing delay caused by the intermittent driving of the Hall elements 2U, 2V, and 2W. The rotation control part 12 allows a phase of the applied voltage to advance based on the advance value generated by the advance value generation part 16.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor drive device that drives a brushless DC motor.

  In recent years, brushless DC motors used as fan motors for air conditioners, air purifiers, etc. have not only reduced power consumption due to the drive inverter, but also reduced power consumption of motor drive devices that drive brushless DC motors. It has been demanded. During normal operation, about 70% of the current consumed by the control power supply of the motor drive device is used to drive the Hall element. In view of this, a technique has been proposed in which a Hall element power supply is intermittently driven with a period sufficiently shorter than the zero cross period of the Hall voltage to reduce current consumption (see, for example, Patent Document 1).

JP 63-39486 A

  However, when the Hall element power supply is intermittently driven as in the prior art, there is a problem that the motor efficiency deteriorates. FIG. 3 is a graph comparing the motor efficiency when the Hall element power source is DC driven and the motor efficiency when the Hall element power source is intermittently driven, and the vertical axis indicates the motor drive current [mA]. The horizontal axis indicates the rotational speed [rpm]. As can be seen from FIG. 3, when the Hall element power source is intermittently driven, the motor drive current is increased and the motor efficiency is deteriorated as compared with the case where the Hall element power source is DC driven. This deterioration in motor efficiency becomes more prominent as the rotational speed increases.

  In view of the above problems, an object of the present invention is to provide a motor drive device that can prevent deterioration of motor efficiency even if a Hall element is intermittently driven.

The motor drive device according to the present invention is configured as follows to achieve the above object.
The motor driving apparatus of the present invention drives a brushless DC motor provided with a hall sensor that detects a magnetic pole of the rotor and outputs a pair of hall voltages with opposite polarities as position detecting means for detecting the position of the rotor. A motor driving device for intermittently driving a Hall sensor by intermittently outputting a driving voltage to the Hall sensor, and a drive circuit for generating and outputting an applied voltage to be applied to a driving winding of the brushless DC motor And a hall amplifier that generates a hall signal by detecting a zero-crossing detection timing at which the hall voltage output from the hall sensor zero-crosses, and a rotational position of the rotor is grasped based on the hall signal generated by the hall amplifier. Rotation control means for driving the drive circuit and the intermittent drive of the Hall sensor And an advance value generating means for generating an advance value that takes into account a delay in locross detection timing, and the rotation control means is based on the advance value generated by the advance value generating means. The phase of the applied voltage output from is corrected.
Further, the motor driving apparatus according to the present invention is a brushless DC motor in which a hall sensor for detecting a magnetic pole of the rotor and outputting a pair of hall voltages with opposite polarities is provided as position detecting means for detecting the position of the rotor. A motor driving device for driving a motor, intermittently driving a hall voltage to the hall sensor to intermittently drive the motor, and generating and outputting an applied voltage applied to the driving winding of the brushless DC motor. Drive circuit, a hall amplifier that detects a zero-crossing detection timing at which the hall voltage output from the hall sensor zero-crosses and generates a hall signal, and a rotor rotational position based on the hall signal generated by the hall amplifier Rotation control means for grasping the drive circuit and driving the drive circuit, and zero of the input Hall voltage An electrical angle predicting means for predicting a loss timing; and an advance value generating means for generating an advance value taking into account a delay in the zero-cross detection timing caused by intermittent driving of the Hall sensor, and the Hall sensor power supply Based on the prediction result by the electrical angle predicting means, the drive voltage is intermittently output in the period immediately before the zero cross of the Hall voltage until the zero cross is detected compared to the period other than the period immediately before the zero cross. A duty ratio is increased, the advance value generation means generates an advance value that takes into account the delay of the zero cross detection timing caused by intermittent driving of the Hall sensor in the period immediately before the zero cross, and the rotation control means Output from the drive circuit based on the advance value generated by the advance value generation means. And correcting the phase of the serial applied voltage.

  According to the present invention, since the advance angle delay due to the delay of the zero cross detection timing due to the intermittent drive of the Hall element can be corrected by the advance angle control, the delay due to the delay of the zero cross detection timing due to the intermittent drive of the Hall element It is possible to prevent the deterioration of the motor efficiency.

It is a block diagram which shows the structure of 1st Embodiment of the motor drive device which concerns on this invention. It is a wave form chart for explaining delay of a hall signal at the time of intermittent drive. It is a figure which shows the deterioration of the motor efficiency by the intermittent drive of a Hall element. It is a block diagram which shows the structure of 2nd Embodiment of the motor drive device which concerns on this invention. FIG. 5 is a waveform diagram illustrating an example of a drive switching signal output from the electrical angle prediction unit illustrated in FIG. 4. FIG. 6 is a waveform diagram for explaining an example of duty ratio switching by the drive switching signal shown in FIG. 5. FIG. 6 is a waveform diagram for explaining an example of duty ratio switching by the drive switching signal shown in FIG. 5. FIG. 6 is a waveform diagram for explaining an example of switching of drive voltages by a drive switching signal shown in FIG. 5.

  Next, embodiments of the present invention will be specifically described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and a part of the description is omitted.

(First embodiment)
Referring to FIG. 1, the motor drive device 1 according to the first embodiment includes a drive circuit 11, a rotation control unit 12, an internal regulator 13, an oscillator (OSC) 14, a hall amplifier AmpU, AmpV, and AmpW. The rotation signal capturing unit 15 and the advance value generating unit 16 are provided.

  The drive circuit 11 obtains power supply from the main power supply VBB, generates and outputs applied voltages UOUT, VOUT, WOUT applied to the drive windings LU, LV, LW of the three-phase brushless DC motor M, respectively. The drive circuit 11 is composed of, for example, six N-channel MOS-FETs or IGBTs connected in a totem pole type.

  The rotation control unit 12 grasps the rotational position of the rotor based on the input hall signals HU, HV and HW, and drives the drive circuit 11 based on the control signal Vsp input from the external control unit ( For example, 6 PWM signals for respectively driving 6 N-channel MOS-FETs of the drive circuit 11 are generated.

  The internal regulator 13 obtains power supply from the control power supply Vcc and supplies power to each part of the motor drive device 1. Further, the internal regulator 13 generates and outputs a driving voltage VReg (for example, 5V) for driving the hall elements 2U, 2V, and 2W attached to the three-phase brushless DC motor M at an electrical angle of 120 °, for example. It functions as a power source for sensors. Hall elements 2U, 2V, and 2W are position detection means that detect the position of the rotor of the three-phase brushless DC motor M, and are Hall sensors that detect a magnetic pole of the rotor and output a pair of Hall voltages with opposite polarities. Then, the Hall voltage output from the Hall elements 2U, 2V, and 2W crosses zero every electrical angle of 180 ° around the partial pressure of the resistor RI and the resistor R2 as the three-phase brushless DC motor M rotates. .

  The internal regulator 13 performs intermittent driving in which the driving voltage VReg is intermittently output based on the pulse signal output from the oscillator (OSC) 14 at a cycle sufficiently shorter than the zero cross cycle of the Hall voltage. A resistor RI, Hall elements 2U, 2V, and 2W connected in parallel and a resistor R2 are connected between the output terminal of the drive voltage VReg and the ground terminal.

  Hall voltages HUP and HUN output from the Hall element 2U are supplied to the Hall amplifier AmpU, Hall voltages HVP and HVN output from the Hall element 2V are supplied to the Hall amplifier AmpV, and Hall voltages HWP and HWN output from the Hall element 2W are Hall. Each is input to the amplifier AmpW.

  The hall amplifier AmpU compares the two input hall voltages HUP and HUN. When the hall voltage HUP becomes higher than the hall voltage HUN, the hall signal HU to be output is switched from the low level to the high level. When the voltage drops below the Hall voltage HUN, the output Hall signal HU is switched from High level to Low level. The hall amplifiers AmpV and AmpW operate in the same manner as the hall amplifier AmpU, and output a hall signal HV and a hall signal HW, respectively.

  Based on the input hall signals HU, HV, and HW, the rotation signal capturing unit 15 generates a rotation signal FG that switches between a high level and a low level, for example, every 60 ° of electrical angle, and generates the generated rotation signal FG. Output to an external control unit.

  The advance value generation unit 16 generates an advance value based on the control signal Vsp input from the external control unit and outputs the advance value to the rotation control unit 12. The rotation control unit 12 advances the phase of the applied voltages UOUT, VOUT, and WOUT based on the input advance value, thereby advancing the winding current, and the advance angle that matches the phases of the induced voltage and the winding current. Make corrections. The generation of the advance value in the advance value generation unit 16 is not limited to the control signal Vsp, but may be performed based on the characteristics of the motor, the rotational speed, the load torque, an external command, or the like.

  2, (a) is a driving voltage VReg at the time of DC driving, (b) is a hall voltage HUP and HUN at the time of DC driving, (c) is a driving voltage VReg at the time of intermittent driving, and (d) is a voltage at the time of intermittent driving. Hall voltages HUP, HUN, and (e) indicate a Hall signal HU during intermittent driving, respectively. In FIG. 2, the frequency at the time of intermittent driving of the driving voltage VReg is shown smaller than the actual frequency for the purpose of explanation. The period of the actual driving voltage VReg during intermittent driving is, for example, 50 μs (frequency is 20 kHz), which is sufficiently shorter than the zero-crossing periods of the Hall voltages HUP and HUN. The zero cross period of the Hall voltages HUP and HUN is about 7.5 ms when the number of poles of the three-phase brushless DC motor M is 8 and the rotation speed is 1000 rpm.

  As shown in FIG. 2A, during DC driving in which a constant driving voltage VReg is applied to the Hall element 2U, the Hall voltages HUP and HUN are continuously output as shown in FIG. The zero crossings of the Hall voltages HUP and HUN can be accurately detected at times t0, t1, and t3. Hereinafter, the timing at which the zero cross of the Hall voltage is detected is referred to as zero cross detection timing. On the other hand, when the drive voltage VReg applied to the Hall element 2U is intermittently driven as shown in FIG. 2C, the Hall voltages HUP and HUN are as shown in FIG. It is output only during the period when the drive voltage VReg is applied to the element 2U. Accordingly, when the drive voltage VReg is not applied to the hall element 2U at time t1, the zero-cross detection timing becomes time t2 when the drive voltage VReg is next applied. The delay of the zero cross detection timing due to the intermittent driving of the hall elements 2U, 2V, and 2W appears as an advance delay for the three-phase brushless DC motor M, resulting in deterioration of motor efficiency.

  Therefore, in the present embodiment, the advance value generation unit 16 is configured to generate an advance value that takes into account the delay of the zero cross detection timing due to the intermittent drive of the Hall elements 2U, 2V, and 2W. That is, the advance angle value generation unit 16 calculates a hole detection delay advance angle correction value that corrects an advance angle delay caused by a delay in the zero cross detection timing due to intermittent driving of the hall elements 2U, 2V, and 2W, and calculates the detected hall detection. The delayed advance angle correction value is added to the advance angle value generated based on the control signal Vsp and output.

  In the advance value generation unit 16, a frequency Fa (period Ta = 1 / Fa) for intermittently driving the Hall elements 2U, 2V, and 2W is set in advance. The advance value generator 16 measures a time Tb of an electrical angle of 1 ° based on the input hall signals HU, HV, and HW. In the hall signals HU, HV, and HW input to the advance angle generation unit 16, the timing at which the high level and the low level are switched is the zero cross detection timing at which the zero cross of the hall voltage is detected, and every 60 ° of electrical angle. The high level and the low level are switched by any one of the hall signals HU, HV, and HW. The advance value generation unit 16 can measure the time Tb of the electrical angle of 1 ° by measuring the interval between the zero cross detection timings (electrical angle 60 ° or 360 °) with the built-in clock.

  Then, the advance value generation unit 16 calculates the hall detection delay advance correction value by dividing the time during which the drive voltage VReg is not applied (for example, 1/2 of the period Ta) by the measured time Tb. That is, the maximum value of the zero-cross detection timing delay due to the intermittent driving of the Hall elements 2U, 2V, and 2W is, for example, 1/2 of the cycle Ta. Therefore, the advance value generation unit 16 detects the hall based on the electrical angle corresponding to the time when the drive voltage VReg becomes 0 V, that is, the electrical angle corresponding to ½ of the period Ta which is the maximum value of the zero-cross detection timing delay. The delay advance correction value is calculated. Note that the delay of the zero-cross detection timing is not necessarily ½ of the cycle Ta, but is in the range of 0 to the cycle Ta. Further, the calculated hole detection delay advance correction value may be multiplied by a coefficient k set to less than 1 and output.

  For example, when the motor rotation speed is 1000 rpm and the motor pole number is 8 poles, the time Tb with an electrical angle of 1 ° is about 41.6 μs. When the frequency Fa of intermittent driving of the hall Fa = 20 KHz (period Ta = 50 μs), the hole detection delay advance angle correction value is 1.2 °.

As described above, in this embodiment, Hall elements 2U, 2V, and 2W that detect the magnetic poles of the rotor and output a pair of Hall voltages with opposite polarities are disposed as position detecting means for detecting the position of the rotor. An internal regulator 13 that functions as a Hall sensor power source that intermittently drives the Hall elements 2U, 2V, and 2W by intermittently outputting drive voltages to the three-phase brushless DC motor M. Drive circuit 11 that generates and outputs applied voltages applied to drive windings LU, LV, and LW of three-phase brushless DC motor M, and zero-cross detection in which the Hall voltages output from Hall elements 2U, 2V, and 2W are zero-crossed Hall amplifiers AmpU, AmpV, AmpW that detect timing and generate Hall signals HU, HV, HW, and Hall signals HU, H , Based on the HW, grasps the rotational position of the rotor and drives the drive circuit 11, and the advance value taking into account the delay of the zero cross detection timing caused by the intermittent drive of the Hall elements 2U, 2V, 2W The rotation control unit 12 corrects the phase of the applied voltage output from the drive circuit 11 based on the advance value generated by the advance value generation unit 16. In correcting the phase of the applied voltage, the phase may be advanced based on the advance value, or the phase may be delayed based on the advance value.
With this configuration, the advance angle delay due to the delay in the zero cross detection timing due to the intermittent drive of the hall elements 2U, 2V, and 2W can be corrected by the advance angle control. It is possible to prevent the deterioration of the motor efficiency due to the delay of the zero cross detection timing.

Further, in the present embodiment, the advance value generation unit 16 calculates a hole detection delay advance correction value that corrects an advance delay due to a delay in the zero cross detection timing, and calculates the calculated hole detection delay advance correction value. An advance value obtained by adding is generated.
With this configuration, it is possible to correct the advance delay due to the delay of the zero cross detection timing by the calculated hole detection delay advance angle correction value, and it is possible to perform the advance angle control more accurately.

Further, in the present embodiment, the advance value generation unit 16 calculates the Hall detection delay advance correction value based on the Hall signals HU, HV, HW and the period Ta for intermittently driving the Hall elements 2U, 2V, 2W. To do.
With this configuration, it is possible to calculate a hole detection delay advance correction value corresponding to the number of revolutions by using the hall signals HU, HV, and HW. In other words, the advance delay due to the delay in the zero cross detection timing increases as the rotation speed increases, but by calculating the hole detection delay advance correction value according to the rotation speed, the advance delay that varies depending on the rotation speed can be obtained. It can be corrected appropriately.

Further, in the present embodiment, the advance value generation unit 16 measures a time Tb of an electrical angle of 1 ° based on the hall signals HU, HV, HW, and intermittently drives the hall elements 2U, 2V, 2W. The hole detection delay advance correction value is calculated by calculating an electrical angle corresponding to 1/2 of the above.
With this configuration, the advance delay can be appropriately corrected based on the maximum advance delay resulting from the zero cross detection timing delay.

(Second Embodiment)
Referring to FIG. 4, the motor drive device 1a according to the second embodiment includes an internal regulator 13a, an advance value generation unit 16a, an electrical angle prediction unit 17, and a PWM control unit 18. It differs from the motor drive device 1 of the form.
The electrical angle prediction unit 17 assumes that the three-phase brushless DC motor M is rotating at a constant rotational speed, and outputs from each of the hall elements 2U, 2V, and 2W based on the hall signals HU, HV, and HW. Predict the zero crossing timing of the hall voltage to be generated. Then, the electrical angle predicting unit 17 switches the drive switching signal Vd to the high level at a timing before the hall voltage is zero-crossed, and when detecting the zero-crossing of the hall voltage, switches the drive switching signal Vd to the low level. It should be noted that an external control signal Vsp for instructing the rotational speed is input to the electrical angle predicting unit 17, and the Hall voltage is detected based on the zero cross detection timing at which the zero cross of the input Hall voltage is detected and the control signal Vsp. The timing before the zero crossing may be predicted. The rotation control unit 12 drives the drive circuit 11 by modulating the duty of the drive signal based on an instruction by the control signal Vsp. The drive circuit 11 controls the rotation speed of the three-phase brushless DC motor M based on the drive signal.

  FIG. 5 shows Hall signals HU, HV, and HW that are input to the electrical angle predicting unit 17. In the hall signals HU, HV, and HW, the timing at which the high level and the low level are switched is the zero-cross detection timing at which the zero cross of the hall voltage is detected, and any one of the hall signals HU, HV, and HW every 60 ° electrical angle. As a result, the high level and the low level are switched. The electrical angle predicting unit 17 first measures the zero-cross cycle T1 of the Hall voltage, that is, the three-phase brushless DC motor M, by measuring the interval between the zero-cross detection timings (for example, time ta to tb, time ta to td, etc.) A time T1 for rotating by an electrical angle of 60 ° is calculated.

  Based on the calculated zero-cross cycle T1, the electrical angle predicting unit 17 switches the drive switching signal Vd to the high level at a timing before the zero-cross cycle T1 elapses from the zero-cross detection timing. For example, as shown in FIG. 5, the electrical angle predicting unit 17 calculates a drive switching time T2 (T2 = T1 * 50/60) that is 10 ° before the zero cross period T1 and drives from the zero cross detection timing. After the switching time T2, the drive switching signal Vd is switched to the high level. For example, when the number of poles of the three-phase brushless DC motor M is 8 and the rotation speed is 1000 rpm, the drive switching signal Vd is set to High level after about 6.25 ms (7.5 ms * 50/60) from the zero cross detection timing. Switch.

  In the present embodiment, the timing for switching from intermittent driving to DC driving is set to 10 ° before the predicted electrical angle of zero cross timing. The value of the electrical angle can be appropriately set in consideration of the mounting error of the Hall elements 2U, 2V, 2W and the shift of the zero cross detection timing accompanying the change in the rotational speed based on the control signal Vsp.

  The PWM control unit 18 generates a PWM (Pulse Width Modulation) signal whose period is a pulse output from the oscillator (OSC) 14 at regular intervals. Note that the period of the pulse output from the oscillator (OSC) 14 is set to a period sufficiently shorter than the zero-cross period of the Hall voltage. Then, based on the PWM signal generated by the PWM controller 18, the internal regulator 13a outputs the drive voltage VReg when the PWM signal is High level, and stops outputting the drive voltage VReg when the PWM signal is Low level. Accordingly, the Hall elements 2U, 2V, and 2W are intermittently driven with a period sufficiently shorter than the zero cross period of the Hall voltage based on the PWM signal generated by the PWM control unit 18.

  The PWM control unit 18 changes the duty ratio of the generated PWM signal according to the drive switching signal Vd output from the electrical angle prediction unit 17. As shown in FIG. 6, the PWM control unit 18 increases the duty ratio of the PWM signal when the drive switching signal Vd is at a high level compared to when the drive switching signal Vd is at a low level. Thereby, in the period immediately before the zero cross is detected from the time before the zero cross of the Hall voltage, the period during which the output of the drive voltage VReg is stopped is shortened.

  The PWM signal generated by the PWM control unit 18 is also input to the advance value generation unit 16a. The advance angle value generation unit 16a calculates the hall detection delay advance angle correction value by dividing the time during which the drive voltage VReg in the period immediately before the zero cross is not applied by the measured time Tb. In the period immediately before the zero cross, the time during which the drive voltage VReg is not applied is shorter than the period other than the period immediately before the zero cross. Accordingly, the hole detection delay advance correction value calculated by the advance value generation unit 16a is also a small value. As a result, the error in detecting the zero cross becomes small, and it is possible to more effectively prevent the deterioration of the motor efficiency due to the delay in the zero cross detection timing caused by the intermittent drive of the hall elements 2U, 2V, and 2W.

  FIG. 7 shows an example in which the duty ratio of the PWM signal is 0% when the drive switching signal Vd is at the low level. In this case, the Hall elements 2U, 2V, and 2W are in a stopped state in which the drive voltage VReg is not applied in a period other than the period immediately before the zero cross, and the power consumption can be further reduced.

  Further, the drive switching signal Vd from the electrical angle prediction unit 17 is input to the internal regulator 13a, and as shown in FIG. 8, the period other than the period immediately before the zero cross (the period when the drive switching signal Vd is at the low level) is the period immediately before the zero cross. The drive voltage may be lowered as compared with (a period in which the drive switching signal Vd is at a high level). That is, when the drive voltage is lowered, the output level of the hall signals HU, HV, and HW is lowered, so that there is a high risk of erroneous detection due to the influence of noise or the like. False detection is allowed. Therefore, power consumption can be further reduced by lowering the drive voltage during the period other than the period immediately before the zero crossing.

As described above, in this embodiment, Hall elements 2U, 2V, and 2W that detect the magnetic poles of the rotor and output a pair of Hall voltages with opposite polarities are disposed as position detecting means for detecting the position of the rotor. An internal regulator 13a that functions as a Hall sensor power source that intermittently drives the Hall elements 2U, 2V, and 2W by intermittently outputting drive voltages to the three-phase brushless DC motor M. Drive circuit 11 that generates and outputs applied voltages applied to drive windings LU, LV, and LW of three-phase brushless DC motor M, and zero-cross detection in which the Hall voltages output from Hall elements 2U, 2V, and 2W are zero-crossed Hall amplifiers AmpU, AmpV, AmpW that detect timing and generate Hall signals HU, HV, HW, Hall signal HU, A rotation control unit 12 that drives the drive circuit 11 by grasping the rotational position of the rotor based on V and HW, an electrical angle prediction unit 17 that predicts zero-cross timing of the input Hall voltage, Hall elements 2U, 2V, An advance value generation unit 16a that generates an advance value that takes into account the delay of the zero-cross detection timing caused by intermittent driving of 2W, and the internal regulator 13a is based on the prediction result by the electrical angle prediction unit 17, In the period immediately before the zero cross of the Hall voltage until the zero cross is detected, the duty ratio for intermittently outputting the drive voltage VReg is larger than the period other than the period immediately before the zero cross, and the advance value generator 16a Add delay of zero cross detection timing due to intermittent driving of Hall elements 2U, 2V, 2W in the previous period To generate the advance value, the rotation control unit 12 corrects the phase of the applied voltage output from the drive circuit 11 on the basis of the advance value generated by the advance value generating unit 16a.
With this configuration, the error in detecting the zero cross is reduced, and the deterioration of the motor efficiency due to the delay in the zero cross detection timing due to the intermittent driving of the hall elements 2U, 2V, and 2W can be more effectively prevented. .

Further, in the present embodiment, the internal regulator 13a sets the duty ratio to 0 percent in a period other than the period immediately before the zero cross, and stops the output of the drive voltage VReg for the Hall elements 2U, 2V, and 2W.
With this configuration, power consumption can be further reduced.

Further, in the present embodiment, the drive voltage VReg is lowered in the period other than the period immediately before the zero regulator and the internal regulator 13a, compared to the period immediately before the zero cross.
With this configuration, power consumption can be further reduced.

Further, in the present embodiment, the electrical angle predicting unit 17 measures the interval between the zero cross detection timings when the zero cross of the input Hall voltage is detected, and predicts the timing before the zero cross of the Hall voltage based on the measurement result. To do.
With this configuration, it is possible to accurately predict the zero cross timing by measuring between the zero cross detection timings.

Furthermore, in the present embodiment, the electrical angle predicting unit 17 determines the Hall voltage based on the zero-cross detection timing at which the zero-cross of the input Hall voltage is detected and the control signal Vsp from the outside that indicates the rotation speed. Predict the timing before zero crossing.
With this configuration, the zero-cross timing can be easily predicted by the control signal Vsp.

The configurations, shapes, sizes, and arrangement relationships described in the above embodiments are merely schematically shown to the extent that the present invention can be understood and implemented, and numerical values and compositions (materials) of the respective components. Is merely an example. Therefore, the present invention is not limited to the described embodiments, and can be modified in various forms without departing from the scope of the technical idea shown in the claims.
For example, Hall elements 2U, 2V, and 2W may be replaced with Hall ICs as Hall sensors, and a plurality of Hall sensors may be connected in series.
The Hall sensor power source may be either a constant current source or a constant voltage source, and the resistors R1 and R2 may not be provided in accordance with the configuration of the Hall sensor power source.
Further, in order to measure between the zero-cross detection timings, not only the internal clock but also an external clock or charge / discharge of a capacitor may be used.

DESCRIPTION OF SYMBOLS 1, 1a Motor drive device 2U, 2V, 2W Hall element 11 Drive circuit 12 Rotation control part 13, 13a Internal regulator 14 Oscillator (OSC)
15 Rotation signal capturing unit 16, 16a Advance value generation unit 17 Electrical angle prediction unit 18 PWM control unit AmpU, AmpV, AmpW Hall amplifier LU, LV, LW Drive winding M 3-phase brushless DC motor VBB Main power supply Vcc Control power supply

Claims (9)

A motor driving device for driving a brushless DC motor in which a Hall sensor that detects a magnetic pole of the rotor and outputs a pair of Hall voltages with opposite polarity is provided as position detecting means for detecting the position of the rotor,
A Hall sensor power source that intermittently drives the Hall sensor by intermittently outputting a drive voltage;
A drive circuit that generates and outputs an applied voltage to be applied to the drive winding of the brushless DC motor;
A hall amplifier that generates a hall signal by detecting a zero-crossing detection timing at which the hall voltage output from the hall sensor zero-crosses;
Rotation control means for grasping the rotational position of the rotor based on the Hall signal generated by the Hall amplifier and driving the drive circuit;
An advance value generating means for generating an advance value taking into account the delay of the zero-cross detection timing caused by the intermittent drive of the Hall sensor,
The motor driving apparatus according to claim 1, wherein the rotation control unit corrects the phase of the applied voltage output from the drive circuit based on the advance value generated by the advance value generation unit.   The advance angle value generation means calculates a hole detection delay advance angle correction value for correcting an advance angle delay caused by a delay in the zero cross detection timing, and adds the calculated hole detection delay advance angle correction value. The motor driving device according to claim 1, wherein a value is generated.   3. The motor driving apparatus according to claim 2, wherein the advance angle value generating unit calculates the hall detection delay advance angle correction value based on the hall signal and a period of intermittently driving the hall sensor.   4. The motor drive device according to claim 3, wherein the advance angle value generation means calculates the Hall detection delay advance angle correction value based on an electrical angle corresponding to a time when the drive voltage becomes 0V. A motor driving device for driving a brushless DC motor in which a Hall sensor that detects a magnetic pole of the rotor and outputs a pair of Hall voltages with opposite polarity is provided as position detecting means for detecting the position of the rotor,
A Hall sensor power source that intermittently drives the Hall sensor by intermittently outputting a drive voltage;
A drive circuit that generates and outputs an applied voltage to be applied to the drive winding of the brushless DC motor;
A hall amplifier that generates a hall signal by detecting a zero-crossing detection timing at which the hall voltage output from the hall sensor zero-crosses;
Rotation control means for grasping the rotational position of the rotor based on the Hall signal generated by the Hall amplifier and driving the drive circuit;
Electrical angle predicting means for predicting the zero-crossing timing of the input Hall voltage;
An advance value generating means for generating an advance value taking into account the delay of the zero-cross detection timing caused by the intermittent drive of the Hall sensor,
The Hall sensor power supply is driven based on a prediction result by the electrical angle predicting means in a period immediately before the zero crossing of the Hall voltage until a zero cross is detected compared to a period other than the period immediately before the zero crossing. Increase the duty ratio for intermittent voltage output,
The advance value generation means generates an advance value that takes into account the delay of the zero cross detection timing due to intermittent driving of the Hall sensor in the period immediately before the zero cross,
The motor driving apparatus according to claim 1, wherein the rotation control unit corrects the phase of the applied voltage output from the drive circuit based on the advance value generated by the advance value generation unit.   6. The motor driving apparatus according to claim 5, wherein the hall sensor power supply sets the duty ratio to 0 percent in a period other than the period immediately before the zero crossing, and stops outputting the driving voltage to the hall sensor.   The motor driving apparatus according to claim 5 or 6, wherein the hall sensor power supply lowers the driving voltage in a period other than the period immediately before the zero cross compared to the period immediately before the zero cross.   The electrical angle predicting means measures between zero-cross detection timings when the input zero cross of the Hall voltage is detected, and predicts the timing before the zero cross of the Hall voltage based on the measurement result. The motor drive device according to claim 5.   The electrical angle predicting means predicts the timing before the zero cross of the Hall voltage based on the zero cross detection timing at which the zero cross of the input Hall voltage is detected and an external control signal that indicates the rotation speed. The motor drive device according to claim 5, wherein the motor drive device is provided.

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